1. Technical Field
The present invention relates to semiconductor devices and fabricating methods, and more particularly to U-shaped structures and methods for semiconductor devices.
2. Description of the Related Art
Fin field effect transistors (finFETs) have become an important option for technologies of 20 nm and beyond. One of the major issues with finFET technology is device width quantization, which causes device design challenges for devices, such as in, e.g., SRAM designs.
In addition, T-shaped fins have been produced, which include the top of the “T” as a base and a vertical portion of the T extending upward from the base. T-shaped fins suffer from thickness control issues of the base of the inverted T. Current processing techniques leave the edges of the base non-uniform on the remaining sections of the base, and the thickness is not well-controlled. These thickness control issues lead to performance issues in the completed device.